As mentioned the sear is the main difference between the standard, and target accu-trigger guns. The sears are same in the way they fit the gun, but the target accu-trigger is cut at a different angle. The target accu-trigger sear is identified by a small dimple just under the bolt release/cocking indicator flag. So to answer your question yes the target accu-trigger set up will fit your standard accu-trigger rifle. The problem is savage will not sell the target accu-trigger parts so your only hope is to find someone that has removed their entire set up.
The Jewel trigger (That was developed for the Savage rifle.) is highly complicated, and needs to be installed by a gunsmith. (Like Arnold Jewel originally did.) The trigger was abandoned due to cost, and compeating against other aftermart, and target accu triggers. The Jewel trigger had no safety, (Or safety feature as the OP desires.) and at lowest setting would only go down to 3-4 oz. Do to the need for a true competition trigger Sharp Shooters Supply stepped up to the plate and developed the "Evolution" trigger. It is a 3 lever design, and the ones I have break at 2oz. The downside is the trigger also needs to be installed by a gunsmith, and cost. It also doesn't have a safety or safety feature that is found on a accu trigger. ( As the OP is requesting.) There has also been a few people that have modified Remington Jewel triggers to fit Savage rifles, and they work fine.